Hackers are demanding ransoms to unlock devices that were locked with the Find My iPhone tool, according to forum posts

Hackers appear to be exploiting Apple's "Find My iPhone" service to lock up phones and tablets and send ransom demands to their owners.

A number of reports on Apple's support forum tell of devices displaying messages that they have been hacked by "Oleg Pliss" and demanding payment of a US$100 ransom via PayPal to unlock them. Most of the reports were from Australians but there were also reports from a Briton and a Canadian.

Image credit: Macworld

The hackers seem to have used the "Find My iPhone" feature or its equivalent for other Apple gadgets to lock the devices and send the message, according to the forum posts that were first highlighted by Australian newspaper The Age.

The feature is meant to help users find their lost or stolen Apple devices. If Find My iPhone is enabled for a lost device, the owner can log into Apple's iCloud service to see where the missing device is located on a map, or track where it has been. Users can decide to immediately lock the missing device, displaying a custom message on the screen.

Some users said they had accessed iCloud and indeed saw that the lost mode was enabled for their devices. However, they were unable to disable the lock mode and regain access to their devices. Others tried to restore the devices to factory settings, which appeared to work for some of them.

An Apple spokesman couldn't immediately comment on the problem, but one forum user reported Apple's customer service is "pretty sure the restore is the only way forward."

It is unclear at the moment how the hackers are gaining access to the devices. One possibility is that they gained access to a database with user names and passwords used for several services, including iCloud. Those login credentials could have been used to enable the lost mode and lock the devices

Image credit: Macworld

At least one of the users said their iCloud password was the same as the one they used for eBay, whose database with login credentials and other personal information was recently hacked, prompting the company to ask its users to reset their passwords. Others said they re-used their password for iCloud, but did not use it for their eBay accounts.

The latest messages on the forum thread are from hacked users who said their AppleIDs have been disabled, leading to speculation that Apple could have started isolating hacked accounts.

Loek is Amsterdam Correspondent and covers online privacy, intellectual property, open-source and online payment issues for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to loek_essers@idg.com